Ink applicator means for downside surface of printing press roll

ABSTRACT

Ink applicator means for applying liquid ink to the downside surface of a printing press roll comprises a hollow ink applicator tube adjacent the downside surface of the roll. The tube has a longitudinal ink outlet slit in one side thereof facing the roll. Elongated ink guide means are provided on the tube below the slit for defining an ink reservoir bounded on one side by a portion of the surface of the roll. The elongated ink guide means have a lower edge adjacent but spaced from the surface of the roll. The ink reservoir assures application of an even, unbroken layer of ink on the roll surface.

Unite States Patent 1 1 1 1 9 Abler June 11, 1974 1 INK APPLICATOR MEANS FOR DOWNStDE 3,326,123 6/1967 Smalley 101/366 x 3,631,800 1/1972 Mignone et a1 101/366 X SURFACE OF PRINTING PRESS ROLL 3,641,932 2/1972 Behringer lOl/366 X [75] Inventor: Norman C. Abler, Menomonee Falls Primary Examiner-Robert E. Pulfrey [73] Assignee: Faustel, Inc., Butler, Wis. Assistant Examiner-Paul T. Sewell a a I I Filed: 48,126,197? Attorney Agen 0r Fzrm James E Nilles lnk applicator means for applying liquid ink to the [52] US. Cl 101/364, 101/157, 101/169 downside Surface of a printing press comprises a [51] Int. Cl 1341f 31/02 hollow ink applicator tube adjacent the downside [58] held of Search 101/1531 face of the roll. The tube has a longitudinal ink outlet 0 335, 366 slit in one side thereof facing the roll. Elongated ink guide means are provided on the tube below the slit [56] Reerences cued for defining an ink reservoir bounded on one side by a UNITED STATES PATENTS portion of the surface of the roll. The elongated ink 2,018,193 10/1935 Smith 101/366 guide means have a lower edge adjacent but Spaced 2,891,471 6/1959 Sengewald 101/169 X from the surface of the roll. The ink reservoir assures 2,935,940 5/1960 Bronstein 101/335 application of an even, unbroken layer of ink on the 3,207,070 9/1965 Klingler et a]. 101 /366 m1] Surface, 3,236,178 2/1966 Worthington et al lOl/366 X 3,273,535 9/1966 Krikorian 101/364 X 3 Claims, 4 Drawing Figures INK APPLICATOR MEANS FOR DOWNSIDE SURFACE OF PRINTING PRESS ROLL BACKGROUND OF THE INVENTION l. Field of Use This invention relates generally to printing presses, such as rotogravure of flexograph presses, and particularly to ink applicator means for applying ink to the downside surface of rolls therein.

2. Description of the Prior Art Rotogravure and flexograph printing presses, for example, employ a rotatable printing cylinder having engraving thereon and an ink applicator adjacent the cylinder for continuously applying ink thereto as the cylinder rotates. Typically, the ink applicator means takes the form of a tube axially sligned with and adjacent the cylinder. The tube is supplied with ink and is provided with a slit in the side thereof near the printing cylinder through which ink emerges. Normally, applicator lips are arranged along the slit to guide the ink emerging therefrom onto the printing cylinder. Such tubes sometimes have a slit which is nominally equal in length to the printing cylinder and have means within the tube to maintain a steady and even flow of ink from the slit. When such ink applicators are used to apply ink to the downside surface of printing cylinders or other rolls in high-speed presses, the peripheral speed of the roll or cylinder to which the ink is being applied tends to tear or interrupt the film of ink being applied, especially if the film is already uneven and the ink is thin. Attempts to overcome this problem have not been entirely successful.

SUMMARY OF THE PRESENT INVENTION In accordance with the present invention there is provided a web printing press, such as a flexographic press, having one or more engraved or etched rolls or cylinders on its downside to which ink is applied. Each such roll is mounted for rotation on the press frame and each is provided with an adjustably movable ink applicator means or assembly adjacent the cylinder for continuously applying ink thereto as the cylinder rotates.- The ink applicator means comprises a hollow tube or member, preferably cyindrical, axially aligned with and adjacent the cylinder and having a chamber therein. The tube is enclosed at both ends and its chamber is supplied with ink through one or more ink inlet ports in the side of the tube. The tube is provided with an elongated slit in. the side thereof near the cylinder through which ink emerges from the chamber.

A longitudinal member is axially disposed within the tube chamber. The longitudinal member has a crosssectional configuration which differs fromthe crosssectional configuration of the tube chamber whereby at least one portion of the longitudinal member cooperates with the wall of the tube chamber to define one or more metering orifices to control passage of ink from an inlet port to the slit. The longitudinal member is provided with depressions in a surface thereof which extend from locations in the vicinity of the inlet port along the longitudinal member to evenly distribute fluid pressure in the chamber.

In accordance with the invention elongated ink guide means are provided on the tube below the slit for defining an ink reservoir which is bounded on one side by a portion of the surface of said roll. The elongated ink guide means have a lower edge adjacent but spaced from the surface of the downside surface of the roll. The hollow tube is rotatably adjustable on its axis with respect to the roll. The elongated ink guide means comprise a first member of L-shaped cross-section which is rigidly secured to the tube. The elongated means further comprise a second member such as a flat plate or extension lip which defines the lower edge; the extension lip being rigidly but adjustably mounted on the bottom of the first member so that it can be adjustably spaced from the surface of said roll.

Since the roll is a downside roll, the ink guide means provide a reservoir of ink which enables any air entrained in the ink as the roll rotates downwardly to escape.

Ink applicator means in accordance with the present invention are especially well-adapted for use on the downside surface of rolls in flexographic presses, but are not so limited in use. Furthermore, the ink applicator means are well adapted for use in presses where the ink applicator assembly must be relatively movable for adjustment with respect to the roll or other press components. The ink applicator means ensure that ink is evenly applied in an unbroken film to the roll. The ink applicator means also enables a very compact and ver- ,satile arrangement of press components. Other advantages will hereinafter appear.

' DRAWINGS f assembly shown in FIG. 1; and

FIG. 4 is a side view of the internal shaft used in the assembly shown in FIG. 1 and 2.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, the numeral 10 designates a flexographic type printing press in accordance with the inventionhaving a web 11 to be printed therein which is understood to be movable in the direction of the arrows 12. In FIG. 1, the right side of press 10 is the downside and the left side is the upside. Press 10 is shown as having six printing stations, three downside and three upside. Downside printing station 14 is typical of the two other downside stations and is hereinafter described in detail.

Downside station l4lcomprises a steel backup roll 15 in contact with the rear unprinted side of web 11, a printing roll 16 preferably formed of rubber or the like for transferring an ink image to the front side of the web; and an engraved or etched metal roll l7which transfers the ink image to printing roll 16. The rolls 15, 16 and 17 are mounted on a support frame 20 of press 10 for rotation in the direction of the arrows shown thereon in FIG. 1.

FIG. 1 shows that station 14 also comprises an ink applicator means or assembly 18. Assembly 18 is shown in detail in FIGS. 2 and 3.

Referring to FIGS. 2 and 3, adjustable ink applicator means or assembly 18 is provided to apply ink to the ports 35. 2

downside surface 22 of downside roll 17 and comprises a pair of support brackets 23 which are rigidly secured to frame 20 on opposite sides thereof and support a hollow shaft or ink supply tube 26 through which a supply of ink flows. lnk supply tube 26 is rotatably adjustable with respect to brackets 23 when bolts 27 on the brackets 23 are loosened and is clamped in fixed position therein by means of bolts 27 when the latter are tightened. Extension arms 28 are rigidly secured to tube 26,- as by welding, and afford support for the ends of a hollow ink feed tube 30. lnk feed tube 30 is rotatably adjustable with respect to arms 28 when bolts 31 on the arms 28 are loosened and is clamped in fixed position therein by means of bolts 31 when the latter are tightened.

As FIGS. 2 and 3 show, ink is transferred from ink supply tube 26 to ink feed tube. 30 by means of an outlet pipe 32 on supply tube 26 which connects to a flexible hose 33, which, in turn connects to a rigid pipe 34. Rigid'pipe 34 is connected to ink feed tube 30 by an inlet pipe or port 35 thereon which also mechanically supports pipe 34. Ink feed tube 30 is provided on its front side i.e., that side facing roll 17 with a slot 37 through which .ink is supplied to the surface 22 of roll 17. Ink guide means 38, hereinafter described, are secured on tube below an opening or slit 37 to assist in proper application of ink to roll 17. In the embodiment shown,ink feed tube 30 is provided with two inlet As FIGS. 2, 3 and 4 show, ink feed tube 30 is provided with a longitudinal member 42 which is axially disposed within the chamber 44 of tube 30. The longitudinal member 42 also. has a cross-sectional configuration which differs from the cross-sectional configuration of the chamber 44 whereby at least one portion of the longitudinal member cooperates with the wall of chamber 44 to define four metering orifices, such as 46, to control ink flow. Member 42 is also provided with two depressions 48 to evenly distribute fluid pressure in chamber 44.

In an actual embodiment of the invention, where chamber 44 had a diameter of l l l 6 inches, the longitudinal member 42 was by )6 inches (with the grooves or'depressions 48 in the narrower side) and each groove 42 was 10 inches long and the distance between the adjacent ends of the grooves was 13 inches.

The diameter of each inlet port was about 16 inch and ink was supplied at a suitable pressure.

Since roll 17 is a downside roll, ink guide means 38 provide a reservoir of ink 60 which enables any air entrained in the ink as roll 17 rotates downwardly to escape. The means 38 comprise a first member inthe form of an L-shaped angle iron 61 secured to tube 30 t by bolts and a second'member such as a flat plate or an extension lip 39 secured to member 61 by bolts 62 and a clamp bar 41. Lip 38 is adjustably movable by loosing the bolts 62 which'extend through slots 63 in plate 39 and moving the plate to-a desired position adjacent the surface 22 of roll 17. End plates such as 64 in the web being improperly printed. This effect is more pronounced, especially, if the ink solution is thin or watery. The effect is principally due to the fact that air or air bubbles become entrained in the film of ink.

The ink guide means in accordance with the invention ensure that a body of ink is in constant contact with a relatively large segment of the roll to which ink is being applied. Any air that is entrained in the ink in the reservoir (due to aerodynamic effects as the roll moves rapidly therepast) is able to bubble up and away from the surface of the roll.

As is apparent from slots 63, shown in FIG. 2, the plate 39 is adjustable to achieve the proper spacing between its edge and the surface 22 of roll 17 so that a layer of ink of desired thickness is applied to the surface.

I claim:

1. In a printing press having a supporting frame and a rotatable cylindrical roll having a cylindrical'surface to which ink is to be applied, the downwardly movable portion of said cylindrical surface during roll rotation being the downside surface of said roll, ink applicator means for applying ink to said cylindrical surface as said roll rotates, comprising:

an elongated hollow ink supply tube mounted on said supporting frame and rotatably adjustable with respect thereto;

extension armmeans rigidly secured to and extending from said ink supply tube;

an elongated hollow ink feed tube mounted on said extension arm means and rotatably adjustable with respect thereto, said ink feed tube being movable to locations adjacent to said roll in longitudinal re lation with respect thereto and spaced from said downside surface of said roll, said ink feed tube having an opening in the side thereof facing said downside surface from which ink emerges for application to. said cylindrical surface of said roll;

and ink guide means for ensuring even application of an unbroken film of ink to the surface of said roll, said ink guide means extending between said ink feed tube from a position adjacent said opening therein to a position adjacent but spaced from said downside surface of said roll, to define an ink reservoir closed at its ends and bounded on one side by a portion of said downside surface of said roll, said ink reservoir being open on its top side to enable air entrained in the ink in said reservoir to bubble up and away from said downside surface of said roll.

2. A printing press according to claim 1 wherein said opening in said ink feed tube is located in a side of said ink feed tube facing said downside surface of said roll;

wherein said ink guidemeans comprises a first member rigidly secured to said ink feed tube below said openplate on said second member. 

1. In a printing press having a supporting frame and a rotatable cylindrical roll having a cylindrical surface to which ink is to be applied, the downwardly movable portion of said cylindrical surface during roll rotation being the downside surface of said roll, ink applicator means for applying ink to said cylindrical surface as said roll rotates, comprising: an elongated hollow ink supply tube mounted on said supporting frame and rotatably adjustable with respect thereto; extension arm means rigidly secured to and extending from said ink supply tube; an elongated hollow ink feed tube mounted on said extension arm means and rotatably adjustable with respect thereto, said ink feed tube being movable to locations adjacent to said roll in longitudinal relation with respect thereto and spaced from said downside surface of said roll, said ink feed tube having an opening in the side thereof facing said downside surface from which ink emerges for application to said cylindrical surface of said roll; and ink guide means for ensuring even application of an unbroken film of ink to the surface of said roll, said ink guide means extending between said ink feed tube from a position adjacent said opening therein to a position adjacent but spaced from said downside surface of said roll, to define an ink reservoir closed at its ends and bounded on one side by a portion of said downside surface of said roll, said ink reservoir being open on its top side to enable air entrained in the ink in said reservoir to bubble up and away from said downside surface of said roll.
 2. A printing press according to claim 1 wherein said opening in said ink feed tube is located in a side of said ink feed tube facing said downside surface of said roll; wherein said ink guide means comprises a first member rigidly secured to said ink feed tube below said opening; and wherein said ink guide means further comprises a second member mounted on said first member and adjustably movable thereon, said second member defining a lower edge spaced from the downside surface of said roll.
 3. A printing press according to claim 2 wherein said first member has an L-shaped cross-sectional configuration and wherein said second member is a plate and further including means for adjustably securing said plate on said second member. 